ASTER ALES. 



513 



red flowers, which are gathered and dried, constituting the dye Saf- 

 flower. 



Centaurea odoratx and C. inoscJiata, from Asia, and other European 

 and American species, are cultivated in flower gardens. 



Cnicus includes our Thistles, most of which are weeds iti fields. 



FIGS 442-5. ILLUSTRATIONS OF TARAXACUM DENS-LEONIS. 



FIG. 442. 



Fm. 44.3. 



Fio. 445. 



Fig. 442. Head of flowers, with a bud on the right, a closed fruiting head on the 

 left, and two leaves. 



Eig. 443. Flower. Magnified. Fig. 444. Receptacle and fruits. 



Fig. 445. Fruit. Magnified. 



/ 



C. arvensis, the so-called Canada Thistle, is in reality an Old World 

 species. It is one of the most difficult of all our weeds to eradicate on 

 account of its underground stems, which are tenacious of life. 

 (7. lanceolatus, the Common Thistle, is another introduced species. 



